Hum Eliminator(TM) 2 - 2-Channel Box with 1/4 inch. "Smart Jacks" (TS or TRS) Model HE-2
Hum X Exterminator
Line Level Shifter 2 - 2-Channel Box with 1/4 inch. "Smart Jacks" (TS or TRS) Model LLS-2
HUMNO AC Noise Eliminator